In recent years, the silicon photonics technology has been developed. This silicone photonics technology is for coupling between an optical device and an electronic device through an optical circuit or wiring using an optical waveguide which is made of a material, such as silicon. In this manner, the optical device and the electronic device are coupled through the optical circuit or wiring. Semiconductor devices having these implemented therein are called optical communication modules.
For example, an optical signal is converted into an electric signal by a photoelectric conversion element in a photoelectric converter of the semiconductor device. The optical signal arrives at the photoelectric conversion element through the optical waveguide. The photoelectrically converted electric signal is then transmitted through wiring.
Japanese Unexamined Patent Application Publication No. 2012-27198 discloses a semiconductor device having a semiconductor layer with an intrinsic semiconductor formed over a substrate and an optical waveguide as a part of this semiconductor layer.